Impact testing on Sport Protections and Mouth guards

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In many Olympic sports, participants are exposed to a high risk of high speed impact scenarios. Even in the ancient Olympics, sports such as wrestling and boxing provided plenty of opportunity for collision and injury. Fortunately in modern Olympic sports, protective clothing is provided that covers most body parts extremely well and modern sports are much safer than their ancient counterparts as a result. One such important piece of protective equipment is the humble mouth-guard, first worn by boxers, but now in common use across many Olympic sports.

But how do you test a mouth-guard? Clearly it’s important to know that the mouth-guard will take the battering applied to it during regular use. That’s where Instron’s CEAST 9350 Drop tower with additional energy system comes in. Not only is the 9350 capable of applying the speed and energy required to simulate a heavy punch from a boxer*, but the additional thermostatic chamber enables temperature conditioning at 37◦c to better replicate the in-situ environment. Moreover, the versatility of the Instron product range means that specialised fixtures can be produced; an embedded transducer can detect force from the tooth’s ‘perspective’, and the material can either be tested as a flat sample or in finished product form on a manikin jaw. Our DAS (Data Acquisition System) can collect data from such customised, additional sensors.

*According to recent research1, a punch is thrown, on average, at a velocity of 9.14 m/s (metres per second) with an effective mass of 8.9 kg. Based on a statistical maximum (assuming normal distribution) of three standard deviations above the average, the worst battering that the mouth-guard will have to protect against is 1,040 joules at 15.32 m/s and 8.9kg; the CEAST 9350’s capacity of 16m/s at 9kg covers this range of testing conditions neatly. Similarly a hockey puck can reach speeds of up to 110 mph (miles per hour), associated with energies of up to 207J, well within the maximum energy range of the 9350’s capabilities.

1Walilko, T J et al. (2005). Biomechanics of the head for Olympic boxer punches to the face. Available here. Last accessed 25th July 2012.

Impact resistance is one of the most important properties for component designers to consider, as well as the most difficult to quantify. Impact resistance is a critical measure of service life and more importantly these days, it involves the perplexing problem of product safety and liability. With the combined experience of Dynatup® and CEAST, Instron® has more than 80 years experience in designing impact testing systems to simulate real-life impact conditions.